1. Field of the Invention
The present invention is related to a so-called "rigid shell" sports boot that includes a shell base overhung by an upper capable of pivoting in both directions, i.e. front-to-rear and rear-to-front, and is related to an immobilization device with respect to the shell base that is active in both the pivoting directions of the upper by means of a rotational manoeuvering member located on the latter, and is especially related to an adjustable immobilization device that is adapted to modify the bending capacity of the upper in at least one direction, depending on the type of use envisioned for the boot at a given moment.
2. Description of Background and Relevant Information
Sports boots of the above-mentioned type are known according to European Patent No. 0 521 282. According to this patent, the immobilization device of the upper with respect to the shell base is active in at least one of its pivoting directions via an abutment zone obtained on the shell base. To this end, the device is equipped with a rotational manoeuvering member including a rotational cam that acts on a mobile element which is adapted, for a given angular position of the cam, to cooperate with the abutment zone of the shell base, and for another given position of the cam, to become disengaged from the abutment zone. As has been disclosed, when the mobile element cooperates with the abutment zone of the shell base, the upper of the boot is systematically blocked towards the rear, i.e., it is forced to adopt an inclination, commonly known as the "angle of advance", and at the same time, it is stopped from any pivoting towards the front or it has a certain clearance before becoming blocked, the blocking being predetermined during construction and resulting from the adjustment between that portion of the mobile element that cooperates with the abutment zone and the upper. Inversely, when the mobile element does not cooperate with the abutment zone, the upper is unlatched, and thus free to pivot as much towards the front as towards the rear.
As is obvious, the immobilization device as described can thus modify the pivoting capacity of the upper between a skiing position, with or without any frontward bending capacity according to the predetermined construction, and a walking-relaxed position in which the upper is free to pivot. Such an immobilization device is satisfactory if all that the user requires is the frontward bending capacity of the upper which has been predetermined in advance. As a matter of fact, one only has one immobilization position in the rear-to-front direction from this immobilization position of the upper in the front-to-rear direction, thus providing only one bending capacity for the upper. However, it is a fact that according to the type of skiing being envisioned, for example, competitive skiing or leisure skiing, or according to the condition of the snow cover, i.e., deep, heavy, icy snow etc., the skier needs to increase or diminish this frontward bending capacity. The immobilization system disclosed thus proves to be ill-adapted because there is no provision, after construction, for modifying the adjustment obtained between its mobile element portion and the abutment zone of the shell base, and thus the bending possibilities of the upper, especially towards the front.